So I just finished putting a computer together. Every part of it is brand new. When I turn it on, it starts fine, but then it beeps 3 times, turns off, and starts again repeating the three beeps, turns off, on again, etc.

From what I've found online, and from the electronics store I called, 3 beeps indicates a ram problem. Is this true? Because if anything is faulty, I'd prefer it to be the ram.

Here the build

GPU: EVGA geforce gtx 660 superclocked
CPU: intel i5-3470 quad core 3.2 ghz
Motherboard: MSI LGA1155 intel B75/DDR3
RAM: Corsair Vengeance 8 gb
Power Supply: Corsair builder series CX 500 watt
Hard Drive: Western Digital caviar blue 500 gb
Case: NZXT Source 220

Here's the specific motherboard
http://www.amazon.com/gp/product/B008S8WA18/ref=oh_details_o00_s00_i05?ie=UTF8&psc=1


I've found videos of people building this exact rig and there's turned out fine.

Make sure you have the RAM seated properly and in the right slot. If you have more than one stick of RAM, remove all but one, and try it in the slot0 or whatever the manual suggests is the slot for one stick of memory. Also, remove the memory and seat it again. Just because it looks properly seated don't mean it is. Both latches should close by themselves if seated correctly.

So before I try that, it is likely a problem with the ram? Either it's not seated properly or it's faulty, correct?

As jjsimp said, remove all but one RAM stick. Leave the final stick in the correct slot, which differs from motherboard to motherboard (this is where the manual comes in handy).

Also, try resetting the CMOS (once again, the manual).

Check and double check if everything is properly inserted/connected and stuff, forgetting to plug in a connector somewhere often happened to me.

Also, check if all the fans are spinning.

The fans do spin

You do have all three power cords plugged in. There is the large 24pin in front of the RAM and the four pin by the processor and keyboard ports. There is also one or two six pin on your graphics board.
Don't forget if it still is not working with the one ram stick to try the other one by itself as well. You should try all the memory sticks singly.
According to the manual for your motherboard, two sticks should be in Slot 2 and 4. Slot 1 is closest to the processor while slot 4 is closer to the 24pin power. You can't really rule out other problems as well. If the memory slots are not getting powered, then you will have the same indication as bad memory. If the slot on the motherboard is bad, it will give the same indication. Most likely, yes it is memory, but other parts can give you the same indications.

3 beeps would indeed be a memory fault. But it could mean a problem with the RAM or with the memory controller or with one of the memory slots or even a bent pin on the cpu . Start by trying one RAM module at a time. If the error persists, you will have to check the CPU

I hope you are swapping RAM with out power and with the power cord removed.
Strange the manual for that board doesn't show single slot occupied map. You may have to try the memory stick in different slots, unless you want to wait for MSI customer support to email you the proper setup for single stick. It should be DIMM1, but I have seen some boards where it was DIMM2.

Is that two 4GB sticks or one 8GB stick you have?

Ok so I moved the memory from slots 1 and 3 to slots 2 and 4. Now when I turn it on, the system starts, no beeps, and it turns off. Then it starts again, then turns off again and repeats. So it's the same thing as before, only now there are no beeps.

2 4gb sticks

It's starting indeed to look like there is something wrong with the RAM or maybe the motherboard.

Ok It doesn't seem to start at all now. I'm worried I just fried the motherboard while reinserting the heat sink

It's very possible you have a bad motherboard, which is the worst part to troubleshoot, because it can appear as just about any other type of error.
Do you have access to other computer system's with perfectly working DDR3 sticks?

Unfortunately not.